Urinary incontinence is believed to affect 15% to 30% of non-institutionalized persons over the age of 60, and more than 50% of elderly persons (over the age of 60) who reside in nursing homes. The presently available modes for the treatment of urinary incontinence fall into four general categories, namely: (i) management apparatus; (ii) behavioral; (iii) pharmacologic; and (iv) surgical.
With respect to the latter, numerous procedures and devices utilized therewith are available to treat urinary incontinence of a variety of etiologies in men, women and children. Among the well-recognized procedures include the use of fluid-filled urinary prostheses which typically comprise a cuff pump and pressure regulating balloon. Exemplary of such devices is the AMS Sphincter 800.RTM., produced by American Medical Systems. Typically, such device is implanted in either the bulbus urethra or bladder neck in men and adolescent males. In females, the cuff portion of such device is placed at the bladder neck.
The cuff of the urinary prostheses, which is filled with fluid, surrounds the urethra and gently squeezes it closed to keep urine in the bladder. To urinate, the cuff is deflated by squeezing the pump several times, which causes the fluid to move from the cuff to the balloon member. Within several minutes after urinating, the fluid atomically flows from the balloon back to the cuff, and as a consequence, causes the latter to become full and squeeze the urethra closed, thus restoring continence once again.
While effective in controlling urinary incontinence, such urinary protheses suffer from numerous drawbacks. In this regard, such urinary protheses are difficult to surgically implant, and can be difficult and embarrassing to operate. Moreover, such urinary protheses are not ideally suited for all types of urinary incontinence, are contraindicated in a variety of patients, and are associated with complications, such as excessive cuff pressure.
An alternative and well-recognized surgical procedure available for those suffering urinary incontinence, and particularly women, is suburethral sling surgery. The specifics regarding such surgical procedure are disclosed in greater detail in the following references: Blaivas, Jerry, G. Successful Pubovaginal Sling Surgery, Contemporary Urology, July, 1993; Blaivas, Jerry G., Treatment of Female Incontinence Secondary To Urethral Damage Or Loss, Urologic Clinics of North America, Vol. 18, No. 2, May, 1991; Raz, Schlomo, Surgical Therapy For Urinary Incontinence. Atlas Of Transvaginal Surgery, W. B. Saunders, 1992, Loughlin, K. R., The Endoscopic Fascial Sling Treatment of Female Urinary Stress Incontinence, J. Urol, 1996, A.P.R.; 155 (4): 1265-7; and Staskin, D. R., et al., The Gore-Text Sling Procedure For Female Sphincteric Incontinence: Indications, Technique And Results, J. Urol, 1997; 15(5): 295-9, the teachings of which are expressly incorporated herein by reference.
Essentially, such surgical procedure involves the formation of a sling, which may comprise a harvested graft from a donor, of the patient's own tissue or an elongate strip fabricated from synthetic material, that is selectively positioned beneath the urethra and secured above or to the abdominal fascia. Alternatively, the opposed ends of the sling may be fixed in place, via a suture and anchored to the pubic bone of the patient or in various other ways such as to sutures or tissue adjacent to the urethra.
While suburethral sling surgery, which includes pubovaginal sling surgery, is considered the procedure of choice for women with urinary incontinence resulting from intrinsic sphincter deficiency (ISD), also referenced as type III stress urinary incontinence, to date, however, such procedure has not achieved widespread popularity. In this regard, although such surgical procedure reportedly has a success rate consistently above over 80%, efforts to popularize this durable technique for all forms of stress incontinence have been hampered by the significant post-operative complications that can arise in those situations where suburethral sling surgery is performed incorrectly. The most common complication of such surgical procedure is caused from placing too much tension on the sling at the time of surgery, which as a consequence causes urinary retention, detrusor instability, or both.
While attempts have been made to provide surgeons with means to properly set the accurate tension within a sling during suburethral sling surgery, such devices have met with limited success. The most well known of such devices include spacers, the latter typically comprising a small spherical body mounted upon the pubic bone of the patient. Spacers typically have a channel formed therein which provides the surgeon with a surface upon which sutures of the free end of the sling may be affixed. While generally effective in providing the surgeon with readily available means for securing the sutures of a suburethral sling in position, such devices do not provide the surgeon with any indication as to the degree of tension in the sling, let alone what impact the position of the sling has with respect to anatomical positioning of and pressure within the urethra.
Further prior art systems and procedures, such as ultrasound, lateral cystourethragraphy, and the Q-tip test, while generally effective in measuring the urethral angle, an important factor in evaluating incontinence surgery, are poorly adapted in providing the surgeon with any kind of indication as to the proper position of and pressure within the urethra during the actual suburethral sling surgery. Among the references discussing such systems include Schaer, G. N. et al., Perineal Ultrasound for Evaluating the Bladder Neck and Urinary Stress Incontinence, Obstet. Gynecol., 1995 February; 85(2): 220-4; and Bergman, A., et al., Negative Q-Tip Test as a Risk Factor for Failed Incontinence Surgery in Woman, J. Reprod. Med. 1989 March; 34(3): 193-7.
Notwithstanding the fact that excessive sling tension has been identified as the major cause for complications in suburethral sling surgery and that crude attempts have been made to address the same, there presently does not exist any system or procedure by which the surgeon performing such operation can quantify during the operation the amount of tension or pressure being imparted by the sling to the urethra. There is further lacking in the art a system and method that, in addition to identifying the amount of tension or pressure imparted by a suburethral sling upon the urethra also provides an indication as to the optimal degree of tension to be imparted by the sling in supporting the urethra, as well as when such optimal amount of tension is attained. Still further, there exists a need in the art for systems and methods that enable the surgeon performing a suburethral sling surgery to identify the proper position of and pressure within the urethra of the patient so that the resultant sling imparts an optimal tension, and hence the desired degree of structural stability to the urethra supported thereby.